The word "provenance" in the art and antiques world refers to the prior ownership of any painting, objet d'art, antique or automobile and as the previously shuttered elite auction world has become readily accessible to the public via the internet, the provenance factor is looming increasingly large as a key determinant of the price of rare and storied auction pieces.

Prior to the coming of the internet, the most sought-after and hence valuable provenance for an objet d'art usually involved royalty or respected public figures with well-known good taste. These people played the role of "taste meister" in validating an object's significance and desirability.

The astonishing rise of the internet over the last two decades has democratized the auction process, enabling an informed international audience to attend almost any auction. The characteristics of this new and much larger audience has changed the weighting of the most valuable "provenance" to include movie stars, music legends and pop culture figures.

Several culturally significant hero machines from the sixties and seventies are going to auction in the near future, and it will be interesting to see just how much their pop culture provenance affects their prices. Foremost amongst them is Janis Joplin's psychedelic 1964 Porsche 356 C 1600 SC Cabriolet (no estimate but at least $1 million), though Steve’s’ (played by academy-award-winning director Ron Howard) 1958 Chevrolet Impala Custom from American Graffiti ($800,000 to $1.2 million), the "Black Beauty" hero car from the 2011 remake of The Green Hornet ($80,000 to $120,000) and a pristine screen-used "General Lee" 1969 Dodge Charger ($100,000 to $150,000) from 1979-1985 CBS TV series The Dukes of Hazzard will also draw considerable interest.

There are also three collector motorcycles coming up: Evel Knievel's Harley-Davidson Stratocycle ($200,000 to $300,000) from the 1977 action film, Viva Knievel!; the Triumph Trophy ridden by the Arthur "Fonzie" Fonzarelli in the 1974-1984 TV sitcom Happy Days ($100,000 - $150,000); and a custom Triumph "Sunset Tripper" Chopper built for Led Zeppelin drummer John Bonham ($30,000 - $50,000).

Janis Joplin's 1964 Porsche 356 SC

Unofficial Estimate: $1,000,000 +

On October 1, 1970, Janis Joplin recorded what was to be her best remembered song, the anti-consumerism anthem Mercedes-Benz. Three days later she died of a heroin overdose. The words of that song are even more poignant when you consider that the highly original artist did in fact own a Porsche and made it a personal trademark, driving the streets of Height-Ashbury in her psychedelic 356 Cabriolet.

The Porsche 356 was the first car that Porsche made, and the car that made the Porsche brandname a household word synonymous with sporting excellence and unfailing reliability. Tales of Porsche 356s traveling more than a million miles without major work are commonplace – no other sports car in history can boast such resilience. Produced over 18 years from 1948 to 1966, 76,313 Porsche 356s were made, with the last two years of production running in parallel with the then new 911, both cars becoming (somewhat ironically) the defacto "badge of success" for so many people who were raised listening to Joplin's music.

These days the 356 which sold for around $4000 during the fifties, has long since passed into collectible car status and although only half the 76,300 original cars are believed to have survived, that's still a remarkably large number for a car that is beginning to regularly fetch $200,000+ at auction.

The most valuable 356 model at auction is the Carrera Speedster, of which only about 140 were made, and predictably, one of these holds the record price at auction for the model. In Monaco on 10 May, 2014, the 1956 Porsche 356 A Carrera 1500 GS Speedster pictured above sold for €840,000 (US$1,155,974) at an RM-Sotheby's auction, setting a high watermark for the model which this car might now break.

If the Porsche 356 to be auctioned were an example of non-remarkable provenance, it would probably sell for somewhere between $100,000 and $130,000, but being the personal car of Janis Joplin, the "Queen of Psychedelic Soul", and painted with the Joplin-commissioned psychedelic paint scheme, it's potential is now upward of five to 20 times that figure, and even that might be underestimating things.

For example, a not dissimilar car in many ways is John Lennon's Rolls-Royce Phantom V, pictured above, which was also painted in psychedelic livery by a much-loved eccentric and creative genius. Like Lennon, Joplin died before her time, another characteristic which drives memorabilia prices skyward. Joplin died of a heroin overdose at just 27 years of age, while Lennon was assassinated in 1980 at age 40.

When it went to auction in June, 1985, Sotheby's estimated the former Beatle's Rolls-Royce would sell for between $200,000 and $300,000. As often happens when several parties want the same unique item at auction, a bidding war drove the price well past the price conventional wisdom would consider it worth, with the hammer finally falling at a staggering $2,299,000. 1`985 marked the peak of the first collectible car boom, but it was one of the most expensive cars ever to have sold at auction at that time. The car was purchased by Jim Pattison Group for use within the company's Ripley’s Believe It Or Not! franchises, inadvertently creating yet another real-life true tale into the bargain.

Janis Joplin was a highly original talent with one of the most recognizable female voices of all time. There's not a lot of genuine Joplin memorabilia out there, and she was deeply loved by her fans. This was HER car and she could be seen regularly driving it around her adopted hometown, the Height-Ashbury district of San Francisco, at a special point in time when it was the global epicentre of the peace-love movement.

Rolling Stone ranked Joplin number 46 in its 100 Greatest Artists of All Time, and it's worth reading Rosanne Cash's tribute to Joplin in that listing. This excerpt captures the essence of the piece: She wasn't just a great woman in rock — at the time she was the woman in rock. Janis really created this whole world of possibility for women in music: Without Janis Joplin, there would be no Melissa Etheridge. Without Janis, there would be no Chrissie Hynde, no Gwen Stefani.

RM-Sotheby's has yet to put an estimate on the car, and may not do so as it could quite possibly go the same way as the Lennon Roller which Sotheby's sold for ten times it's estimate in 1985. This car is a landmark piece of cultural memorabilia, as original and distinctive as it's owner.

1969 "General Lee" Dodge Charger

Auctioneer's Estimate: $100,000 - $150,000

Most movies and TV series use several identical cars for each of the identifiable feature vehicles, as mishaps, stunts and breakdowns cannot disrupt the far-more-costly filming process. The Dukes of Hazzard TV series which ran on CBS from 1979 to 1985 created a very different dynamic due to its obligatory trademark cars stunts in every episode.

From the auction description: This car has all the hallmarks of a studio “hero” car: the inside door panel hardware (door lock and handles) were removed by the production crew to enable the actors to easily slide in and out of the car through the door windows, and a custom front center seat was installed so that an additional actor could ride in the front – most often this was Katharine Bach, who played “Daisy”. The car was originally blue, and the interior of the trunk and engine compartment still retains this color scheme, as this car was most certainly acquired by the crew in some of the later seasons and painted in the “General Lee” paint scheme. The wheels are original, and the interior has been re-upholstered. Some exterior paint touch-ups have been done in the years since the production ended, and the decals on either side of the Confederate flag have been refreshed. Though the turn signals are not currently working, the car remains in good running condition and is completely street legal and drivable. The car has a clear title, and is accompanied with a letter of authenticity from Warner Bros. stating that this car was used as a “General Lee” picture vehicle during the filming of the series. Also included with the car is an original production Hazzard County license plate for the General Lee with license number “CNH 320” (not original to this car, but used on another General Lee on the series). These license plates are extremely rare, as most were removed and subsequently lost after the production wrapped; only three are believed to have survived. A rare opportunity to own an original, screen-used General Lee – one of the most recognizable cars in television history.

In addition to the becoming the definitive American baby boomer coming-of-age movie, American Graffiti emphasized the significance of the automobile in this process, offering a nostalgic look at California’s youth car culture of the 1960s.

In the blockbuster film, this car (Lot 1531 at Profiles in History's Hollywood auction, September 30 to October 1, 2015)featured in much of the action and was owned by Steve Bolander (Ron Howard) and driven by "The Toad" (Charles Martin Smith), along the way becoming one of the most famous cars in American cinema history.

Perhaps most importantly, the car has been owned by the same person since 1973, after being purchased via an advert posted in The San Francisco Chronicle on behalf of George Lucas. Hence the car is exactly as it was when it appeared in the film, with the original studio white paint with red trim, and the original studio-customized red and white tuck and roll upholstery. The car retains the 348 cubic-inch high-performance Chevrolet V-8 mated to a Turbo 400 automatic transmission, though the original Saginaw three-speed manual transmission used in the film comes with the car. Original in every respect, it even comes with the original California DMV-validated registration card issued to Lucas Film all that time ago (42 years ... feeling old?).

Fonzie's 1949 Triumph Trophy TR5 (Happy Days)

Auctioneer's Estimate: $100,000 - $150,000

There's an irony that this bike should appear at auction on the same card as the American Graffiti Chevrolet Impala, as the top-rating 1970s TV sitcom Happy Days came about due to the success of the movie.

What's more, this is the Triumph Trophy TR5 motorcycle (Lot 1065 at Profiles in History's Hollywood auction, September 30 to October 1, 2015) that helped make Arthur "The Fonz" Fonzarelli (played by Henry Winkler), the icon of cool in the long-running ABC sitcom. "The Fonz" became the breakout star of the show which was watched by around 40 million Americans at its ratings peak during the decade-long run (1974-1984).

The bike was originally owned by Bud Ekins, racer, Hollywood stuntman and provider of bikes to the studios. Ekins was the rider of the bike which jumped the barbed-wire fence in The Great Escape, doubling for his friend and partner-in-many-shennanigans, Steve McQueen.

One of three Triumph motorcycles "The Fonz" used during the show’s ten-year run on ABC, the other two went missing and are unlikely to ever resurface. When the show ended, Ekins sold the only remaining "Fonzie" Triumph (this bike) to friend and motorcycle collector Mean Marshall Ehlers who has owned it since since 1990. The motorcycle was presented to Ehlers at a Seminole Indian casino by Henry Winkler.

Designed to accommodate Henry Winkler’s inability to ride larger bikes, Ekins had supplied Paramount’s show producers with the beat-up Scrambler, yanking off the front fender, bolted on a set of buckhorn handle bars and spray painted the fuel tank silver. It is often rumored that Winkler was frequently pushed on the bike by stage-hands (confirmed by his own admissions) due to his inability to ride a motorcycle.

Fonzie’s silver Triumph became a pop culture icon, appearing on countless lunch boxes, posters, t-shirts, model kits and magazines. When the show was cancelled, one of Fonzie’s signature brown leather jackets was gifted to The Smithsonian. The "cool factor" of this Triumph is impossible to quantify or duplicate. The bike remains untouched since last appearing in the original show over 30 years ago. Though only estimated to sell for between $100,000 and $150,000, we think the bike is a certainty to become one of the top 100 most valuable motorcycles of all-time.

Evel Knievel's Harley-Davidson XLCH 1000 "Stratocycle"

Estimate: $200,000 - $300,000

Evel Knievel is one of the most recognizable names in entertainment history, forging the way for extreme motorcycle stuntmen the world over with 70+ ramp-to-ramp jumps, a Grand Canyon jump and a world record for the number of broken bones he sustained in doing so. Knievel is listed in the Guinness Book of Records for having suffered the "most bones broken in a lifetime" with a grand tally of 433 (ouch!). Five of his jumps still rank within the top 20 most-watched programs on ABC's Wide World of Sports, and another of his bikes is in the Smithsonian National Museum of American History.

If you don't remember Evel Knievel's "Stratocycle", don't feel bad, because it was used in a film that not many people saw. The bike began life as a 1976 Harley XLCH Sportster 1000 cheesily modified to look like the American Eagle, with wings and a faux rocket rear end and it was used in the 1977 action film, Viva Knievel!, one of the most embarrassingly awful films ever produced.

If you were a kid at the time, or had kids at the time, it's quite possible you came across a toy version of the "Stratocycle" made by Ideal Toy Company. The "Stratocycle" toy has become the most valuable and collectable of all Evel Knievel toys, and this bike (Lot 1374 at Profiles in History's Hollywood auction, September 30 to October 1, 2015) comes with all the documentation to validate its authenticity, so it'll be interesting to see how it fares on the auction block.

"Black Beauty" (The Green Hornet)

Estimate: $80,000 - $120,000

This car is a screen-used “Black Beauty” hero car from The Green Hornet. (Sony, 2011) Based on a 1965 Chrysler Imperial, Dennis McCarthy of Vehicle Effects in California built this hero car used for "beauty" exterior shots and interior close-ups.

This is also the car (Lot 1813 at Profiles in History's Hollywood auction, September 30 to October 1, 2015) that was featured on an episode of Jay Leno’s Garage. It comes with a Sony Pictures California title and a signed letter of authenticity from builder Dennis McCarthy. In fine production used condition, this is one of only two hero cars remaining from the production.

John Bonham’s Triumph “Sunset Tripper” chopper

Estimate: $30,000 - $50,000

This is the custom Triumph "Sunset Tripper" chopper ridden in the epic documentary film The Song Remains the Same. Led Zeppelin commissioned Ron Hagest, owner of California-based Burbank Customs, to create Triumph-based choppers for each of the band members and this bike was built for drummer John Bonham, inspired by the "Captain America" chopper from Easy Rider.

Hagest designed and built the motorcycles based on a rigid, hard-tail frame with customized twisted-steel "springer" front forks and stacked rectangular headlights. Replete with the Union Jack paint scheme on the gas tank and high back seat with sissy bar, each member of the band had his particular "rune" or symbol (Bonham’s being three intersecting circles, as seen on the cover of their fourth album) welded and chromed on the sissy bar. The engine used is from a 1970 T120 Triumph 650cc Bonneville.

In a recent interview, Hagest fondly recalls in September 1972 shipping the disassembled motorcycle via airfreight to John Bonham’s country estate called Old Hyde Farm at Cutnall Green in Worcestershire and assembling it for him on his property. One of Bonham’s passions was vintage cars and motorcycles. In The Song Remains the Same (filmed the summer of 1973; released in 1976), Bonzo can be seen riding this "Sunset Tripper" in the English countryside during his memorable dream sequence.

The motorcycle remained with the Bonham family since his untimely death in 1980 until 1988 when Jason Bonham sold it to the present owner. Between 1988 and December, 2014, this motorcycle has been displayed in a pizza parlor in Denmark. (Lot 1875 at Profiles in History's Hollywood auction, September 30 to October 1, 2015)